Cannot compare with mazda 6. That one also not selling well especially the 2.5L model. Ppl here who wants a D segment car look for a spacious car, comfortable and quiet cabin. These 3 things are Mazda 6 weakness compare to the rest of the D segment competition. Pros of Mazda 6 lies in the steering wheel which gives the best feedback and adequate weight, and the interior design and premium material.
If ppl want a big d segment and need alot of power, can always go for the new passat with detuned golf gti engine.